It could be Roman feature just inside a church (4)
I believe the answer is:
font
I believe this is a double definition.
'it could be roman' is the first definition.
(as in Roman fonts or typefaces)
'feature just inside a church' is the second definition.
(baptismal font)
(Other definitions for font that I've seen before include "Typeface; vessel" , "Size and style of type" , "Gothic" , "Baptismal bowl" , "Baptismal basin" .)